services.AddHangfire(x => x.UseCouchbaseStorage(configuration, "familyPhotos_hangfire"));
Posts tagged with 'F'
Jonathan Danylko talks to Matt about the results of the 2019 Stack Overflow developer survey. We kinda go all over the place for this episode!
This episode is not sponsored! Want to be a sponsor? You can contact me or check out my sponsorship gig on Fiverr
Show Notes:
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This episode is a bit different than normal episodes. It’s an informal discussion of the Stack Overflow survey results by two people who are not and have never been Stack Overflow employees. We discuss a few things that stood out to us, but we barely scratch the surface of all the data that you can dig through. Make sure to check out the survey results yourself for the entire picture!
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We talk a bit about remote work. If you’re interested in that, I recorded a whole episode with Gino Ferrand and published it last week last week.
Want to be on the next episode? You can! All you need is the willingness to talk about something technical.
Jamie Phillips is writing infrastructure as code. This episode is not sponsored! Want to be a sponsor? You can contact me or check out my sponsorship gig on Fiverr
Show Notes:
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HCL, and yes it does kinda look like CSS
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It was just last week, but make sure you don’t miss Jamie’s episode on Packer!
Want to be on the next episode? You can! All you need is the willingness to talk about something technical.
Andy Beeker is watching Office Space. This episode is not sponsored! Want to be a sponsor? You can contact me or check out my sponsorship gig on Fiverr
This episode is different than a normal episode of Cross Cutting Concerns!
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This episode is about an R-Rated movie! Normally my podcast is G-rated, but that is not the case for this episode. If you normally listen with children, I recommend you listen to Story Pirates with them instead!
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This is a long episode: almost an hour. Normally my episodes are around 15 minutes.
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This is an episode about a (vaguely) technical/computer related movie. I’ve done a couple of episodes like this in the past: 071 - Bill Sempf on Sneakers and 036 - Kevin Groves on Pirates of Silicon Valley.
Show Notes:
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We watched Office Space, a 1999 film by Mike Judge. If you haven’t watched it, you should!
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Inside joke alert: the mention of a "white jimmy". This is a reference to a GMC Jimmy SUV that’s painted white. But suppose someone came up to you and said "I have a white Jimmy" and then paused for 15 seconds…
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There are many tangents we go on in this episode. Confused? Send me a question, and I will try to clarify.
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K*Pax - a film you’ve probably never heard of starring Kevin Spacey, Jeff Bridges, and (notable for this podcast) Ajay Naidu.
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Speaking of Kevin Spacey, if you’re out of the loop, you might want to read up on Anthony Rapp.
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The video discussed briefly in the episode is 7 Things You (Probably) Didn’t Know About Office Space
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Adult Swim is the late night block of Cartoon Network that showed King of the Hill in syndication.
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Be sure to check out the Office Space soundtrack.
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Speaking of the "year 2000 switch", check out episode 100 - with Joe Kelly on COBOL.
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We mentioned Tiger LCD games. Here’s a refresher if you don’t quite remember them.
What movie should I tackle next time? Leave some feedback and let me know!
Want to be on the next episode? You can! All you need is the willingness to talk about something technical.
Merry Christmas! This is the last day of the C# Advent. Make sure to check out all of the other great posts from 2017 and 2018. If you want to be involved next year, look for C# Advent 2019 author sign ups at the end of October 2019, and look for blog posts to start showing up on December 1st, 2019.
What is a background job?
A background job is some code that runs apart from the normal flow of your program. It could be run asynchronously and/or on another thread. As an ASP.NET MVC developer, I tend to think of it as any task that runs outside of an MVC action being invoked.
There’s two kinds of background jobs that I’m aware of:
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Scheduled - a task that runs every N minutes, or every Y hours, etc. This is what I’m going to show in this post today. It’s great for making periodic checks, ingesting data from some other source, etc.
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Fire and forget - Some other piece of code kicks off a process to run in the background. It doesn’t block the code (fire), and the code doesn’t wait for a response (forget). This is great for potentially time consuming operations like checking inventory, sending emails, etc, that you don’t need a user to wait for.
What you usually need to do to create background jobs
In my experience, I’ve seen background jobs take a few different forms.
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Separate Windows service (or Linux daemon, whatever). A console/service program that’s running in addition to your ASP.NET program. This works fine for scheduled jobs.
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Queueing mechanisms like Kafka or Rabbit. The ASP.NET program will put messages into these queues, which will then be processed by some other program. This is fine for fire-and-forget.
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Background jobs running within the ASP.NET process itself. In my experience, I’ve used Quartz.NET, which can run within the ASP.NET process. There’s also FluentScheduler (which I’ve not used, and doesn’t seem to come with database integration out of the box?)
With all these options in the past, I’ve experienced deployment difficulties. The wrong version of the service gets deployed, or isn’t running, or fails silently, or needs to be deployed on multiple servers in order to provide scalability/availability etc. It’s totally possible to overcome these challenges, of course. (I should also note that in my experience with Quartz.NET, I never used it in embedded form, and the last time I used it was probably 6+ years ago).
But if I just need a handful of background jobs, I’d much rather just make them part of the ASP.NET system. Yes, maybe this goes against the whole 'microservice' idea, but I don’t think it would be too hard to refactor if you decided you need to go that route. I solve my deployment problems, and as you’ll see with Hangfire (with Couchbase), it’s very easy to scale.
How hangfire works
You can find more details and documentation about Hangfire at Hangfire.io. Really, there are only three steps to setting up Hangfire with ASP.NET Core:
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Tell ASP.NET Core about Hangfire
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Tell Hangfire which database to use
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Start firing off background jobs
In Startup.cs, in the ConfigureServices
method:
Then, in Startup.cs, in the Configure
method:
app.UseHangfireServer();
I’m using Couchbase in this example, but there are options for SQL Server and other databases too. I happen to think Couchbase is a great fit, because it can easily horizontally scale to grow with your ASP.NET Core deployments. It also has a memory-first architecture for low latency storage/retrieval of job data. Generally speaking, even if you use SQL Server as your "main" database, Couchbase makes a great companion to ASP.NET or ASP.NET Core as a cache, session store, or, in this case, backing for Hangfire.
The configuration
variable is to tell Hangfire where to find Couchbase:
var configuration = new ClientConfiguration
{
Servers = new List<Uri> { new Uri("http://localhost:8091") }
};
configuration.SetAuthenticator(new PasswordAuthenticator("hangfire", "password"));
(In my case, it’s just running locally).
Steps 1 and 2 are down. Next, step 3 is to create some background jobs for Hangfire to process. I’ve created an ASP.NET Core app to assist me in the cataloging of all my family photographs. I want my application to scan for new files every hour or so. Here’s how I create that job in Hangfire:
RecurringJob.AddOrUpdate("photoProcessor", () => processor.ProcessAll(), Cron.Hourly);
Note that I didn’t have to implement an IJob
interface or anything like that. Hangfire will take any expression that you give it (at least, every expression that I’ve thrown at it so far).
Step 3 done.
Hangfire is just a NuGet package and not a separate process. So no additional deployment is needed.
How do I know it’s working?
Another great thing about Hangfire is that is comes with a built-in dashboard for the web. Back in Startup.cs, in Configure
, add this code:
app.UseHangfireDashboard("/hangfire", new DashboardOptions
{
Authorization = new[] {new HangfireAuthorization()}
});
I’m using my own HangfireAuthorization
implementation because Hangfire only gives permission to local users by default.
Then, you get a nice dashboard right out of the box, showing you a realtime and history graph.
From this dashboard, you can also look at a more detailed history of what’s run and what’s failed.
You can even kick off recurring jobs manually.
This is only the start
If you’re thinking about adding background jobs to your ASP.NET Core solution, why not give Hangfire a try?
Some more things for you to explore:
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Scaling: every ASP.NET Core site that gets deployed with Hangfire that points to the same database will be able to process jobs too. As your ASP.NET Core site scales out, hangfire scales out with it. This is another reason that Couchbase is a good fit, because it’s also easy to scale out as your site grows.
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Cloud: If you are deploying your site as an app service, note that Azure will shut down ASP.NET processes if they haven’t been used in a while. This means Hangfire will shut down with them. There are a couple of ways to deal with this. Check out the Hangfire documentation.
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Retries: Hangfire will retry failed jobs. Design your background job code to expect this.
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Hangfire Pro: The commercial version of Hangfire is called Hangfire.Pro, and it comes with some interesting looking batch capabilities. I’ve not needed any of this functionality yet, but for more advanced cases you might need this.
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Couchbase: a NoSQL data platform that has a built-in memory-first cache layer, SQL support, text search, analytics, and more. There are lots of options for working with Couchbase in .NET. For this post, I used the Hangfire.Couchbase library (available on NuGet).
Steve Hicks is speaking at conferences. This episode is sponsored by Smartsheet.
Show Notes:
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Mailing list: Technically Speaking by Chiu-Ki and Cate
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Cream City Code conference in Milwaukee
Want to be on the next episode? You can! All you need is the willingness to talk about something technical.
Music is by Joe Ferg, check out more music on JoeFerg.com!